利用\chiEFT 通过氘核康普顿散射确定中子极化率
摘要
手征有效场论（Chiral Effective Field Theory）是光子能量高达 200 MeV 时通过氘核康普顿散射精确确定中子极化率的工具。多极分析表明，来自显式 Delta(1232) 的色散效应对于理解在 SAL 测量的 95 MeV 数据尤为不可或缺。源自核现象学的简单幂次计数论证导出了正确的 Thomson 极限和规范不变性。在次领头阶，静态标量偶极极化率在现有数据的误差范围内被提取为质子和中子相同：中子的值为 \alpha^n=11.6\pm1.5_stat\pm0.6_Baldin, \beta^n=3.6\mp1.5_stat\pm0.6_Baldin（单位 10^-4 fm^3），而同一框架下质子的值为 \alpha^p=11.0\pm1.4_stat\pm0.4_Baldin, \beta}^p=2.8\mp1.4_stat\pm0.4_Baldin。例如在 MAXlab (Lund) 进行的新实验将改善统计误差限。
引用
@article{arxiv.0710.2924,
title = {Neutron Polarisabilities from Deuteron Compton Scattering in \chiEFT},
author = {Harald W. Griesshammer},
journal= {arXiv preprint arXiv:0710.2924},
year = {2008}
}
评论
10 pages LaTeX2e, including 7 figures in 16 .eps files embedded with includegraphicx. Uses MENU07macros (provided). Invited contribution to the 11th International Conference on Neson-Nucleon Physics and the Structure of the Nucleon MENU 2007, Juelich (Germany), 10th -- 14th September 2007. To be published in the electronic proceedings